The pain on the left side of the right breast, if it is on the outside of the breast and has no relationship with the breast, it is considered to be caused by costochondritis, which is mostly accompanied by pain aggravated when the head is lowered, and there is no redness or swelling locally, and there will be pain when it is pressed, which can be treated by oral nonsteroidal anti-inflammatory drugs, and can also be treated with external rheumatism ointment drugs. If the pain is located inside the breast, mainly manifested as pain before menstruation, can be palpated to the lump, the pain disappears after menstruation, the lump disappears, considered to be caused by breast cystic hyperplasia, without special treatment. If the pain is not relieved after menstruation and the lumps continue to exist, oral treatment can be given by taking Easy Pills or Xiaojin Pills. If solid nodules are detected in the breast and pain is obvious, breast ultrasound or mammogram is needed. If the grade is below grade 3, most of the lesions are benign and the chance of malignancy is less than 2%. If the classification is above grade 3, the possibility of malignancy increases, and early comprehensive treatment, mainly surgery, is needed.